Decarboxylated half esters of hydroxylated fatty oils and alpha unsaturated polycarboxylic acids



Patented July 16, 1946 DROXYLATED FATTY OILS AND ALPHA UNSATURATED POLYCARBOXYLIC ACIDS Maynard C. Agens and Birger W. Nordlander,

Schenectady, N. Y., assignors to General Electric Company, a corporation of New York No Drawing. Application January 20, 1943, Serial No. 472,988

19 Claims. 1

The present invention relates to polymerizable resinous compositions comprising decarboxylated partial or half esters of hydroxylated fatty oils, such as castor oil or hydrogenated castor oiLand I an alpha unsaturated polycarboxylic acid. It is concerned particularly with compositions of this type capable of being polymerized by application of heat to a solid state.

In the copending patent application, Serial No. 422,905 (now Patent 2,373,527), filed December 13, 1941, in the name of Maynard C. Agens and assigned to the same assignee as the present invention are disclosed and claimed synthetic resinous compositions comprising decarboxylated partially esterified alpha-unsaturated polycarboxylic acids in which the ester group or groups were derived from monoor polyhydric alcohols. The partial esters were generally prepared by reacting an alpha unsaturated polycarboxylic acid, such as maleic acid or its anhydride, with an alcohol in proportions such that about one-half of the carboxyl groups of the acid'remained unesterified in the reaction product. The partial ester was heated with decarboxylating agents such as pyridine, quinoline, nicotine, piperidine, and their homologues capable of decarboxylating the free carboxyl groups of the acid. The resulting products were heat-polymerizable.

The present invention is concerned with polymerizable compounds of the above general type in which'the alcoholic radical is one derived from castor oil or an equivalent polyester of a long chain hydroxy fatty acid and a polyhydric a1- cohol. The free hydroxyl groups of the fatty acid radicals are reacted with an alpha unsaturated polycarboxylic acid, specifically an alpha unsaturated alpha, beta dicarboxylicacid such as maleic acid or its anhydride, in proportions such that the principal products are acid or half esters of the polycarboxylic acid. Decarboxylation of these half esters by heating with a decarboxylating agent has been found to result in the formation of oily or syrupy resinous compositions which polymerize on heating to a solid, infusible,

and somewhat elastic or flexiblestate and which are particularly useful for making castings, as filling compounds, etc.

Particularly useful compositions are obtained by copolymerizing the decarboxylated products with other compatible polymerizable compounds, e. g. styrene and the higher methacrylic esters such as butyl methacrylate, capable of polymerizingby virtue of the polymerizable i (c1. zso zs) Butyl methacrylate has been found to be an ideal 1 material for this purpose when elastic or flexible products are desired. Styrene gives a more rigid copolymer which is elastic or flexible at elevated temperatures. Another composition useful for the production of heat-hardened cast bodies or filling compounds is a mixture of at least twenty per cent by weight of the decarboxylation prodnot with raw castor oil. Such mixtures may be modified by the addition of butyl methacrylate or the like.

The following examples will serve to illustrate typical compositions falling within the scope of the present invention:

Example 1 Castor oil 742.5 g. (0.8 mol) Maleic anhydride 157.5 g. (1.6 mols) The above ingredients were heated together for 46 minutes, the temperature rising to 179 C. The acid value dropped from an original 200 to 101 showing that the ,anhydride reaction resulting in the formation of a maleic ester had taken About 10 g. (0.12 mol) pyridine was added A25 per centsolution of the resinous product i in monomeric butyl methacrylate was used to gel,

a large quantity of raw castor oil in the following manner:

- Parts by weight 25% solution of resin in butyl methacrylate 25 Castor oil containing 1 benzoyl peroxide The above ingredients were thoroughly mixed and the mixture heated in an C. oven. An infusible, flexible gel was formed in one-half hour. The heat-gellable. mixture was particularly adapted for use as a heat-hardenable filling com pound for electrical apparatus.

Example 2 Castor 011 462 g. (.5 mon Maleic anhydride 73.5 g. (.75 mol) The above were heated together for one-half hour at C. to 178 C. The product, consisting essentially of the half ester, was cooled to 3 121 C. and about g. (0.18 mol) pyridine added and the resultant mixture heated for 2 hours at 121 to 228 C. to form a reddish, viscous resin having an acid value of 39. The resin solidified,

in bulk when heated witha polymerization catalyst such as ben'zoyl peroxide.

A gellable composition prepared from this resin had the following composition:

, Parts by weight Resin 1 25. v Butyl niethacrylate -a Castor oil Benzoyl peroxide a 0.5

This composition gelled to an elasti heated for 80 minutes at 80 7,

Example 3 A heat-gellablecomposition consisting of castor i oil and the decarboxylated maleic anhydridecastor :oil reaction product of Example 2 was made as follows: Castor; oil containing benzoyl peroxide Resin. of Example 2 1 -e. 30 This mixture could be gene- 1 by heating to 'Pa'rts byweight 80C. for 2 hours. The exact gel time 'depends synthetic rubbers such as Hycar are swelled by anyof these castor oil products. In some cases the natural and synthetic rubbers exert a slight inhibiting effect on theigellation of the portion of the filling compound in direct contact with thefrubber but this effectmay be overcome by coating the surface of the rubber prior to intro I ducti'on of the filling compound with a'suitable lacquer.

Example 4* This example illustrates the preparation of a flexible infusiblecopolym'er of the decarboxyl'ate'dcastor oil-maleic anhydride esterification product andibutyll' methacrylate.

I A'solutionof '75 g. of the liquid resin of Example 2 in g butyl methacrylate was mixed with 160g. additional but yl meth-acrylate and 0.375 g. benzoyl peroxide. The copolymer formed by heating the'mixture for 15 hours at 50 C., 8 hours at C., and 8 hours at C. was an infusible, flexible solid which at elevated temperatures was very rubbery and elastic. It had a dielectric constant-of 6.4 at a frequency of 60 cycles and 3.6 at 1000cycles. It was found to be useful for the samelapplications as the castor oil gels of the previous examples. 7

Example 5 V A styrene copolymer was prepared by heating a mixture of 10 parts styrene and 1 part of the at 1500* c. resultedin the 'formatinnlof arigid product which became fl'exible'but 'di'd'fnot deing with a'peroxide' catalyst.

4 form at C. Unlike polystyrene, the copolymer does not flow at elevated temperatures. At 150 C. the product had a power factor of 0.003 at 60 cycles. The same, copolymer containing 7 5 per cent flint as a filler had a dielectric constant of' 3.8 and a power factor of 0.003 at 40 megacycles at room temperature.

Although maleic anhydride and pyridine have been used in illustrating the manner in which the: present. invention may be carried into effect,

-it is to be understood that other alpha unsaturated polycarboxylic acids and other decarboxylating'a'gents may be substituted for thesespeciffie materials asv is set forth more fully in the above-mentioned patent application, Serial No,

'422,905.'-Examp1es-of other suitable alpha unsaturated polycarboxylic acids are fumaric acid, itaconic, acid, and aconitic acid. The alpha unsaturated, alpha, beta dicarboxylic acids such as maleicand fumaric acids are preferred since the free carboxyl groups in the mono-esterification. products of either of these acids are readily decarboxylated to form terminal CH2=CH groups irrespective of which carboxyl group of the. acidreactant has become esterified by reaction. with the hydroxyl groups on the fatty acidradicals. Decarboxylati'ng agents found suitable for the practice of the present invention are those selected from the group consisting of pyridine,

qui'noline, nicotine, .piperidine; and their homologues. A The hydroxylated fatty oil. half-esters of the alpha unsaturated acids or. their anhydrides may theoretically be formed by'reacting the oil and acid in equimolecular proportions. However,

faster reaction ratesand better products are obtained when the mol ratio of polycarboxylic acid to fatty oil. is somewhat greater than 1:1,

for, example about 1.521. When 3 mols maleic anhydride were reacted with 1. mol castor oil and. the resulting product decarboxylated by treatment with pyridine, a very viscous, reddish resin having an acid value of 77 was obtained. The product polymerized quite rapidly on heat- In general, we prefer to react at least' one and. not exceeding approximately two mols of alpha unsaturated polycarboxylic acid with each mol of castor oil as the products so obtained are most easily handled in the preparation of copolymers or gels,

The amount of decarboxylating agent used need. not exceed the; minimum' quantity found necessary to decarboxylate the free carboxyl.

, groups. In general, fromv 0.1 to 0.3 mol of decarboxylating agent is sufficient.

The oily resinous d-ecarboxylation. products of per mol polycarboxylic acid this invention may be employed in applications other than those which are specifically mentionedhereinbefore. Since they exhibit good curing and air-drying properties, particularly in the presence of sicca-tives, they may be. used in the preparation of coating compositions, impreg- 1 nating compositions, insulating compositions, etc.

-- 1;.A polymerizabledecarboxylated partial esterification product of a hydroxylated fatty oi-l and an alpha unsaturated polycarboxylic acid obtained by heating apartial- -esterification product of a hydroxylated fatty oil and an alpha unsaturated polycarboxylic acid containing free carboxyl groups with an amine selected from the oil acid ester of an alpha unsaturated polycarboxylic acid obtained by heating apartial esterification product of a hydroxylated fatty oil and an alpha unsaturated polycarboxylic acid containing free carboxyl groups with an amine selected from the group consisting of pyridine, quinoline, nicotine, piperidine, and their homologues and (2) a methacrylic ester of an aliphatic alcohol compatible with (1) 4. The heat-cured composition of claim 3.

5. A composition as in claim 3 wherein the alpha unsaturated polycarboxylic acid is an alpha unsaturated alpha, beta polycarboxylic acid.

6. A heat-curable composition of matter comprising (1) a polymerizable compound obtained by heating (a) a partial esterification product .of poly ester of a long chain hydroxy fatty acid and an alpha unsaturated dicarboxylic acid, about one-half of the carboxyl groups of the dicarboxylic acid component of said ester being unesterified, with (b) a cyclic amine selected from the group consisting of pyridine, nicotine, quinoline, piperidine, and their homologues to effect decarboxylation of unesterified carboxyl groups of said alpha unsaturated dicarboxylic acid and (2) castor oil.

7. A composition of matter capable of forming a stable gel on heating comprising a major portion of castor oh and a minor portion of a polymerizable resinous material obtained by heating a partial esterification product of castor oil and an alpha unsaturated dicarboxylic acid with a cyclic amine selected from, the group consisting of pyridine, nicotine, quinoline, piperidine, and their homologues to effect decarboxylation of unesterified carboxyl groups of said alpha unsaturated dicarboxylic acid.

8. A composition of matter capable of being converted to a non-fusible stable gel on heating comprising castor oil and at least 20 per cent by weight of a polymerizable resinous material obtained by decarboxylating a partial esterification product of castor oil and maleic anhydride by heating said partial esterification product with a decarboxylating agent selected from the group consisting of pyridine, nicotine, quinoline, piperidine and their homoloogues.

9. A heat-gellable composition of matter comprising castor oil and at least 20 per cent by 11. A composition of matter comprising castor oil and at least 20 per cent by weight of a polymerizable composition comprising a decarboxylated acid ester of an alpha unsaturated, alpha, beta dicarboxylic acid and castor oil obtained by heating said acid ester in the presence of a decarboxylating agent selected from the group consisting of pyridine, nicotine, quinoline, piperidine, and their homologues.

12. A composition of matter comprising (1) a resinous material obtained by heating a partial ester of castor oil and an alpha unsaturated alpha, beta polycarboxlic acid in the presence of a cyclic amine selected from the group consisting of pyridine, quinoline, nicotine, piperidine, and their homologues to effect decarboxylation of the unesterified carboxyl groups of said ester and. (2) a methacrylic ester of an aliphatic alcohol compatible with (1) 13. A composition as in claim 12 wherein the methacrylic ester is butyl methacrylate.

14. A heat-curable composition of matter comprising (1) a polymerizable liquid obtained by heating a partial esterification product of one mol of castor oil and from 1 to 2 mols maleic anhydride with pyridine to effect decarboxylation of unesterified carboxyl groups in said partial esterification product and (2) styrene.

15. A heat-gellable composition of matter coma prising castor oil and a butyl methacrylate solution of a polymerizable liquid Obtained by heating a partial esterification product of one mol of castor oil and 1 to 2 mols maleic anhydride with from 0.1 to 0.3 mol of pyridine per mol maleic anhydride to effect decarboxylation of unesterified carboxyl groups in said partial esterification product.

16. A process which comprises forming a partial ester of an alpha unsaturated polycarboxlic acid and a hydroxylated fatty oil and decarboxylating the free acid group by heating said partial ester in the presence of a decarboxylating agent selected from the group consisting of pyridine, quinoline, nicotine, piperidine, and their homologues.

17. A process Which comprises heat-reacting a hydroxylated fatty acid oil with an alpha unand their homologues to decarboxylate the unesterified carboxyl group.

18. The process which comprises forming a castor oil acid-ester of maleic acid and decarboxylating the unesterified carboxyl groups on said acid-ester by heating said ester in the presweight of a decarboxylated partial ester obtained ence of a decarboxylating agent selected from the group consisting of pyridine, quinoline, nicotine, piperidine, and their homologues.

19. The process which comprises heating a hydroxylated fatty acid oil with maleic anhydride to form a half ester of maleic acid and heating said half ester with pyridine to decarboxylate the free carboxyl groups of said half ester.

MAYNARD C. AGENS. BIRGER W. NORDLANDER, 

